JuliaMath / JuliaMath/DoubleFloats.jl

Matrix exponential throws error

Open
#127 3 comments 0 reactions 0 assignees View on GitHub
Dominant language
Julia
Stars
172
Forks
37
PR merge metrics
No merged PRs in 30d

Description

I tried calculating a matrix exponential but
```julia
julia> exp([1 2; 3 4])
2×2 Matrix{Float64}:
51.969 74.7366
112.105 164.074

julia> exp(Double64.([1 2; 3 4]))
ERROR: MethodError: no method matching svdvals!(::Matrix{Complex{Double64}})
```
I thought it worked with an older version, so I tried (randomly) v1.1.15 and it worked (v1.1.21 did not work):
```julia
julia> exp(Double64.([1 2; 3 4]))
2×2 Matrix{Complex{Double64}}:
51.968956198705 + 0.0im 74.73656456700321 + 0.0im
112.10484685050481 + 0.0im 164.07380304920983 + 0.0im
```
However, for some reason it tourned out complex.

Update:
I did some more tests. v1.1.18 ist the last version that works (with complex output).
In v1.1.19 and v1.1.20 eigen! seems missing.
v1.1.18 has Generic SVD in its dependencies that, given the name, might be connected.

Contributor guide

No contributing guide indexed for this repository

Assessment

This issue has not been assessed yet.

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.